c. 1400, "belonging to (religious) ritual," also as a noun, "a ceremonial practice," from Late Latin caerimonialis "pertaining to ceremony," from caerimonia (see ceremony). Related: Ceremonially.
Ceremonial means connected with or constituting or consisting of or fit for a ceremony (i.e. a piece of ritual or formality) or ceremonies .... Ceremonious means full of or resulting from ceremony i.e. attention to forms .... [Fowler]